1. Technical Field
The present invention relates to wireless communications and, more particularly, to methods and systems for operating multi-mode communication devices.
2. Description of Related Art
More people than ever are using mobile stations, such as cell phones and personal digital assistants (PDAs), to communicate via wireless wide area networks (WWANs), which are also referred to as cellular wireless communication systems, cellular wireless networks, radio access networks and by other names. WWANs typically provide both voice and data communication using a wireless communication format such as Code Division Multiple Access (CDMA), or another format, and typically cover relatively large geographic areas (cities, states, etc.), and are available to the service provider's (i.e. the WWAN operator's) customers generally.
Furthermore, wireless local area networks (WLANs) are becoming increasingly popular. Typical WLANs cover an area that is geographically smaller than that covered by typical WWANs, and often provide a signal in that area that is superior to that provided by the WWAN in the same location. As examples, a WLAN may cover a residence, a building, or a proximally-located group of buildings, perhaps on a corporate or academic campus. Unlike WWANs, WLANs are typically operated by a private individual or organization, and access to the WLAN is typically limited thereto, and to those to whom access data (e.g. a password) is provided.
WLANs typically provide a wireless coverage area and access to a packet-data network via one or more “access points.” A common use of a WLAN is packet-data communication by a laptop computer, or perhaps by another device such as a digital video recorder or another appliance or computer. A commonly-used set of protocols for wireless communication between and among these access points and devices are those specified by the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, often referred to as “IEEE 802.11x.”
Recently, the telecommunications industry has witnessed widespread growth in the area of voice-over-IP (VoIP) technology; that growth, combined with the ever-increasing prevalence of mobile stations engaging in packet-data communication generally, has caused the industry to introduce mobile stations (“multi-mode devices”) that are equipped to engage in both (i) voice and data communications via WWANs (using, e.g. CDMA) and (ii) packet-data communications (including VoIP communications) via WLANs (using, e.g. IEEE 802.11).
In one arrangement, for instance, a service provider may operate one or more gateways that provide connectivity between a packet-switched network (e.g. the Internet) and the service provider's transport and signaling networks. The carrier may then distribute multi-mode devices to its subscribers, where those devices are capable of (a) communicating in a WWAN mode with one or more types of WWANs and (b) communicating in a WLAN mode with one or more types of WLANs. And these devices are typically also able to operate in a combined WWAN/WLAN mode, in which the devices can at least monitor and perhaps engage in communication sessions (e.g. voice calls and data sessions) with both types of networks.
When a multi-mode device is communicating with a WWAN, the device may operate conventionally as a standard cellular telephone, with signaling passing through the service provider's signaling network and bearer data passing through the service provider's transport network. On the other hand, when the multi-mode device is communicating with a WLAN, the device may engage in IP-based signaling and IP-based bearer communication via the WLAN with the service provider's gateway(s), which may then interface the signaling and bearer communications with the service provider's signaling and transport networks.